In-situ blade sharpener

Abstract

A blade sharpening device easily connectable to a source of rotating power, such as a battery powered hand drill, and having a housing, a selectably locatable pitch adjuster and a clamping mechanism means for maintaining the housing and grinding surfaces of the sharpening device at a desired grinding angle. The housing extends completely over the width of the rotatable drums wrapped with grinding surface. By clamping the device directly to the blade and stabilizing the device in this position, the operator has greater control and stability of the sharpener when in use on, for example, a lawn mower blade which is still attached to the lawn mower drive shaft at the underside of the lawn mower housing. This on-site, in-place blade sharpening capability eliminates the necessity of removing the blade for its sharpening, while still allowing easy and safe sharpening of the blade.

1 . A blade sharpening device, comprising: 
 a grinding member having a rotatable grinding surface adapted to grind an edge of desired dimensions on a blade;    a shaft member, secured to said grinding member, having an end thereof adapted for connection with a source of rotational power; securing means for securing said grinding member to said shaft member;    a housing defining a receiving means comprising an upper plate and a lower plate between which said blade may be inserted and a grinding member cavity therein adapted to allow said grinding member to rotate about an axis of a longitudinal aperture, when said grinding member is secured by said securing means to said shaft member in a manner such that said grinding member is surrounded by said housing;    a clamping mechanism, attached to said housing, having a means for adjusting said upper plate to compress said blade against said lower plate to immobilize said blade during an application of said rotating grinding surface against said edge of said blade.    
   
   
       2 . The blade sharpening device of  claim 1 , wherein said clamping mechanism is detachable and includes a means for allowing said clamping mechanism to be mounted in more than one location on said housing.  
   
   
       3 . The blade sharpening device of  claim 2 , wherein said clamping mechanism is detachably mountable perpendicularly to and parallel to said axis of said longitudinal aperture of said grinding member.  
   
   
       4 . The blade sharpening device of  claim 1 , wherein said clamping mechanism includes a cylindrical bore and a cylindrical portion which are companionately threaded.  
   
   
       5 . The blade sharpening device of  claim 1 , wherein said grinding member slides horizontally along said shaft by a manual means of applying a directional force to a pitch adjuster attached to said grinding member.  
   
   
       6 . The blade sharpening device of  claim 1 , wherein said grinding member moves horizontally along said shaft by a mechanical threaded shank.  
   
   
       7 . The blade sharpening device of  claim 1 , wherein a pitch adjuster is affixed to said grinding member to allow for a preferred angle to be formed between said grinding surface and said edge of said blade.  
   
   
       8 . The blade sharpening device of  claim 1 , wherein said grinding member includes a circular band of grinding surface that defines a formed aperture through which a first cylinder and a second cylinder, spaced at a predetermined distance so as to secure said circular band of grinding surface in a taught position and causing said axis of said longitudinal aperture to be centered between said first cylinder and said second cylinder.  
   
   
       9 . The blade sharpening device of  claim 8 , wherein said means for securing said grinding member to said shaft member is adapted to allow the detachable securing of said first cylinder and said second cylinder.  
   
   
       10 . A method of sharpening a blade of a lawn mower or the like while said blade remains attached to a drive member of said lawn mower or the like, said method comprising the steps of: 
 (a) attaching a blade sharpening device to an electrically powered, portable, multi-purpose, multi-use power source producing rotating movement, such as a portable power drill, which device includes:    a grinding member having a rotatable grinding surface adapted to grind an edge of desired dimensions on a blade;    a shaft member, secured to said grinding member, having an end thereof adapted for connection with a source of rotational power; securing means for securing said grinding member to said shaft member;    a housing defining a receiving means comprising an upper plate and a lower plate between which said blade may be inserted and a grinding member cavity therein adapted to allow said grinding member to rotate about an axis of a longitudinal aperture, when said grinding member is secured by said securing means to said shaft member in a manner such that said grinding member is surrounded by said housing;    a clamping mechanism, attached to said housing, having a means for adjusting said upper plate to compress said blade against said lower plate to immobilize said blade during an application of said rotating grinding surface against said edge of said blade.    (b) grasping the housing of said sharpening device in one hand and said portable power source in the other;    (c) adjusting the location of the housing to allow the grinding member access to said edge of said blade;    (d) positioning said grinding member on said blade in a desired location;    (e) securing said clamping mechanism on said blade in said desired location;    (e) initiating transmission of rotational power from said source of rotational power to said shaft and said grinding member; and    (f) moving said grinding member along said shaft across said blade while said grinding member is in contact with said blade and while the position of said blade sharpening device is controlled said secured clamping mechanism.